Spoked Wheel

Abstract

The present invention provides a spoked wheel comprising:a rim comprising a continuous series of circumferential sections each of which has opposed ends and is connected at each of its ends to an adjacent section by means of a hinge that allows the two adjacent sections to pivot with respect to each other substantially in the plane of the wheel;a hub that rotates with the rim; anda plurality of spokes extending between the hub and the rim and supporting the rim on the hub, each spoke having an end that is pivotally attached to the rim via a pivot.At least one of the spokes is movable with respect to the hub in the plane of the wheel to change the angular spacing between adjacent spokes and alter the shape of the rim between a circular shape and a non-circular shape, preferably a flattened shape.The wheel may also include a tubular tyre held on the rim and is primarily intended for use in connection with bicycles and wheelchairs.

Description

TECHNICAL FIELD [0001]The present invention relates to spoked wheels, especially for bicycles and wheelchairs in general and for collapsible wheelchairs or bicycles (that is to say bicycles that have a frame that can be changed from a configuration where the bicycle can be ridden to a more compact configuration for carrying or storage).[0002]However, the present invention is not only limited to bicycles and wheelchairs but to any vehicle that includes or can include spoked wheels or to any application where a wheel is needed but it would be beneficial to be able to reduce the amount of space it occupies when not in use.BACKGROUND ART [0003]Folding bicycles and wheelchairs are well known and include a frame that will fold. However, the wheels used are a fixed size and the size of the wheels limits the size that the bicycle or wheelchair can be folded into (the “package size”).[0004]Small wheels have certain disadvantages when the bicycle or wheelchair is being used. Small wheels have...

AI Technical Summary

Benefits of technology

[0015]Each spoke extends generally across the whole diameter of the wheel; diametric spokes provide a simpler mechanism, are simpler to operate and are stronger than spokes that extend only between the hub and the wheel rim.

[0017]In order to simplify the design and minimise the weight of the wheel, the number of rim sections will generally be kept to a minimum. For the same reason, the number of spokes is preferably kept to a minimum and one embodiment provides a pair of spokes that extends diametrically across the wheel in an “X” configuration. In this case, the rim may comprise six sections, four of which are attached to the respective ends of the two spokes and two of which lie between the ends of the spokes where the spacing between the two ends increases when the wheel is folded. This additional section provides the increased length of the wheel in the non-circular folded configuration.

[0018]A lock may be provided to lock the spokes relative to each other, particularly in the unfolded circular wheel configuration. In addition, the rim sections and the spokes are tensioned against each other when the wheel is in the unfolded configuration, partly to ensure that the rim sections are forced to form a circular shape, even under the weight of the vehicle and its user, and partly to prevent the components of the wheel from rattling. The ends of the spokes and the rim sections may be so configured that, when in the circular unfolded configuration, the ends of the spokes bear against their adjacent rim sections and apply a radial force thereto.

Problems solved by technology

However, the wheels used are a fixed size and the size of the wheels limits the size that the bicycle or wheelchair can be folded into (the “package size”).

Small wheels have certain disadvantages when the bicycle or wheelchair is being used.

Small wheels have higher rolling resistance in contact with the road than larger wheels, meaning that the bicycle or wheelchair is harder to propel and so is slower.

In the case of bicycles, smaller diameter wheels generate lower gyroscopic forces than larger wheels, making them less stable to ride.

On the other hand bicycles and wheelchairs with large wheels cannot be folded into such small packages as those with smaller wheels, making them harder to store and more unwieldy to carry and transport.

The rolling resistance of such an arrangement is very high and it would be difficult to propel such a wheelchair.

Such an arrangement is complex and heavy.

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